This invention relates to thermal insulation and more particularly to an improved construction for thermal insulating panels.
The ever increasing demands for energy and the continually increasing costs of basic fuels have spurred interest not only in energy conservation in general, but, in the increased utilization of thermal insulation in particular. The general efficacy of thermal insulation has been long recognized and expedients ranging from the use of "dead air" space; the use of solid materials of low thermal conductivity; the use of fibrous and cellular materials; the use of coated papers or wallboards of low thermal conductivity; the use of reflective materials, such as aluminum foil, and various combinations and permutations thereof have long been employed for both industrial and residential purposes. In the practical utilization of most of such expedients, the degree of obtainable insulative effect, commonly expressed in terms of an "R" number--normally defined as the ratio of the material thickness divided by its thermal conductivity--is generally proportional to the thickness and/or quantity of insulating material employed. A particular area of concern is that of high temperature environments where, in addition to conventional insulating functions, it is oftentimes desirable to direct and/or delay heat transfer, to assure selectively directed heat transfer or confinement to a given zone or area such as in reaction vessels, piping and the like.